Scratch

so that you don't need to download, here is the script for sensing the walls

when I receive 
sense ▼
delete 
all  ▼
 of 
distances ▼
set 
drawing ▼
 to 
1
set 
distance ▼
 to 
0
set 
scanning remembering thingamajig ▼
 to 
48
repeat 
24
because I have 4 sensors
set 
distance ▼
 to 
60
go to 
movement ▼
the movement sprite
point in direction 
direction ▼
 of 
movement ▼
 + 
scanning remembering thingamajig
repeat until 
touching 
wall ▼
?
 or 
distance
=
0
move 
1
 steps
change 
distance ▼
 by 
-1
add 
distance
 to 
distances ▼
change 
scanning remembering thingamajig ▼
 by 
-1

and here is the script for drawing the walls

when I receive 
draw ▼
go to x:
1
 y:
180
since each drawer takes half the screen
set pen size to 
5
set pen color to 
clear
pen up
set 
help counting ▼
 to 
24
since each distances list is 24 items long
repeat 
24
set pen shade to 
item 
help counting
 of 
distances ▼
*
1
+
2
/
3
set y to 
item 
help counting
 of 
distances ▼
*
4
pen down
set y to 
item 
help counting
 of 
distances ▼
*
4
*
-1
pen up
change 
help counting ▼
 by 
-1
set pen shade to 
0
change x by 
5
because the pen size is 5

Each drawer does that script twice to match up with the 4 lists of distances. I'm trying to figure out how to fix that when it senses, it draws it in a curved room when it's supposed to be straight. Can someone please help me?

Last edited by TorbyFork234 (2012-04-13 16:49:17)

AtomicBawm3 wrote:

The reason is because you're using purely distance.  If you use purely distance, even if points are on the same line that's perpendicular to your view, they're different distances.  This creates the Fisheye effect.  In order to correct this, take the distance you get when scanning and multiply by the cosine of the offset of the angle (i.e. if you're drawing the part of the wall right in the middle, the offset is 0 degrees and so the distance will simply be multiplied by 1).

How do I find the offset of the angle? I tried turning 1 degree, moving 1 step, and seeing if it's still touching the wall, and if not, take that direction and continue going. but that didn't work.

so the new script should be

add 
distance
*
cos ▼
 of 
scanning remembering thingamajig
 to 
distances ▼

?

Also, what's FOV?

Last edited by TorbyFork234 (2012-04-13 17:21:08)

AtomicBawm3 wrote:

Yep, looks like it from the way you've got your scripts set up.    I hope this helps...what you could do is change you FOV from 96 to something more like 60 as well...that will reduce the effect as well.  That would mean at the beginning:
Sensor 1 variable: 30
Sensor 2 variable: 15
Sensor 3 variable: 0
Sensor 4 variable: -15

But that would also reduce the resolution so I won't do it.

bump

no, I tried that and everything up close was fine, but everything far away was all wacky. and then I tried

60
-
cos ▼
 of 
variable
*
60
-
distance

and that didn't work either.

Didn't work. Help anyone?